Active matrix display devices, which have a plurality of pixels arranged in matrix, have been in widespread use. In general, the pixel includes a transistor, a scan line electrically connected to a gate of the transistor, and a signal line electrically connected to one of a source and a drain of the transistor. The display device also includes a controller for controlling the potential of the scan line and the potential of the signal line, and a data signal supplied to each pixel is controlled with the controller.
In recent years, with an increase in concern for the global environment, attention has focused on the development of low-power consumption display devices. For example, Patent Document 1 discloses a technique for reducing the power consumption of a display device by reducing the rewriting frequency thereof. The structure of the display device disclosed in Patent Document 1 will be specifically described below.
In the display device disclosed in Patent Document 1, set are a scanning period for scanning one screen, and a break period which follows the scanning period and is longer than the scanning period. According to the technique disclosed in Patent document 1, during the break period, the potential of a scan line is fixed to the potential of a non-selection signal while (1) the potential of a signal line is fixed to a predetermined potential, (2) the potential of a signal line is fixed to a predetermined potential and then brought into a floating state, or (3) an alternating-current driving signal having a frequency lower than or equal to that of a data signal is supplied to a signal line. Thus, it is possible to reduce the power consumed when the potential of the signal line varies during the break period.